<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        table {
            border: 1px solid #000;
            text-align: center;
            width: 240px;
        }

        th, td {
            border: 1px solid #000;
        }

        h3 {
            position: relative;
        }
    </style>
</head>
<body>

<div id="app">
    <h3>小黑的礼物清单</h3>
    <table>
        <tr>
            <th>名字</th>
            <th>数量</th>
        </tr>
        <tr v-for="(item, index) in list" :key="item.id">
            <td>{{ item.name }}</td>
            <td>{{ item.num }}个</td>
        </tr>
    </table>

    <!-- 目标：统计求和，求得礼物总数 -->
    <p>礼物总数：{{total}} 个</p>
</div>
<script src="../lib/vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
            // 现有的数据
            list: [
                {id: 1, name: '篮球', num: 1},
                {id: 2, name: '玩具', num: 4},
                {id: 3, name: '铅笔', num: 15},
            ]
        },
        computed: {
            total: function () {
                return this.list.reduce((sum, item) => sum + item.num, 0)
            }
        }
    })
</script>
</body>
</html>